Diagnosing and treating subacute cardiac dysfunction

ABSTRACT

A method for diagnosing subacute cardiac dysfunction is performed by electrocardiographically monitoring an ambulatory patient who has persistent unexplainable fatigue and determining the frequency when the T-wave of the ambulatory patient is not positive to determine that subacute myocarditis or a cardiomyopathy is present. This monitoring is preferably performed by a portable monitor and the data is magnetically stored so as to permit subsequent analysis. A treatment is prescribed, preferably restricting activity and refraining from the intake of alcohol as well as antiviral chemotherapy and immunomodulators, when there is an excessively high frequency of the T-wave not being positive. Recovery is determined by further electrocardiographic monitoring of the ambulatory patient and noting when the normally positive T-waves are present all, or at least almost all, of the time.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of pending prior applicationSer. No. 938,439 filed on Aug. 31, 1992 by Albert M. Lerner under thetitle "Diagnosing and Treating Subacute Myocarditis" as acontinuation-in-part of prior application Ser. No. 675,542 filed on Mar.25, 1991 by Albert M. Lerner under the title "Diagnosing and TreatingChronic Fatigue Syndrome By Electrocardiographic Monitoring Of T-Waves",the former of which issued on Oct. 25, 1994 as U.S. Pat. No. 5,357,968,and the latter of which issued on May 25, 1993 as U.S. Pat. No.5,213,106.

TECHNICAL FIELD

This invention relates to a method for diagnosing and treating apreviously unrecognizable subacute cardiac dysfunction byelectrocardiographic monitoring.

BACKGROUND ART

The medical community now recognizes a condition of unknown cause thatis referred to as chronic fatigue syndrome. The role of cardiacdysfunction in this syndrome, the diagnosis and preferred treatment havenot been heretofore understood or explainable. A competent diagnosis forfatigue will conventionally include a complete medical history, aphysical examination and appropriate laboratory studies in order todetermine whether the fatigue can be explained by other diagnoses suchas arteriosclerosis or other coronary artery disease, heart muscledamage from. coronary thrombosis or other acute heart disease, or heartdamage such as pericarditis, etc. Other recognizable infections or otherdiverse maladies may, of course, cause chronic fatigue; but, asmentioned above, this chronic fatigue syndrome has not been heretoforeunderstood or diagnosable. Also, while some consider chronic fatiguesyndrome to exist only when it persists for six months or longer, othersconsider this syndrome to be present when there is an unexplainablefatigue for much shorter periods of time such as one or two months.

Conventional diagnosis for heart disease includes electrocardiographicmonitoring which has been done for many years such as disclosed, forexample, by U.S. Pat. Nos.: 3,267,934 Thornton; 3,572,321 Bloomfield etal; 3,829,766 Herz; and 4,275,742 Faisandier. Most electrocardiographicmonitorings are performed on a sedentary patient; however, it is alsoconventional to electrocardiographically monitor an ambulatory patientsuch as disclosed by U.S. Pat. Nos.: 4,183,354 Sibly et al; 4,457,315Bennish; 4,546,776 Bellin et al; 4,583,553 Shah et al; and 4,883,065Kelen.

Conventional analysis of electrocardiograms of both sedentary andambulatory patients has recognized that heart disease can be diagnosedfrom a persistent abnormality in the PQRST waveform generated by theelectrocardiographic monitoring. For example, when the PQRST waveformfor a patient almost always has depressed ST segments or depressedT-waves, it is recognized that this is an indicator of a lack ofmyocardial oxygen that can result from arteriosclerosis, heart damagesuch as from coronary thrombosis or pericarditis. Prior art whichdiscloses analysis of electrocardiographic data includes U.S. Pat. Nos.:3,605,727 Zenevich et al; 3,858,034 Anderson; 3,868,567 Ekstrom;4,622,980 Kunig; 4,784,153 Marks; 4,854,327 Kunig; and 4,987,901 Kunigas well as Chest Magazine, November 1988 article by Terrence J. Montagueand the commentary on this article by the inventor of the presentapplication in analyzing T-wave depression and inversions.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a method for earlydiagnosis and treatment of a previously unrecognizable subacute cardiacdysfunction of a patient who has unexplainable fatigue.

In carrying out the above object, the method is performed on the patientwith persistent unexplainable fatigue while the patient is ambulatorysuch as during a 24 hour period during which the frequency is determinedwhen the T-wave is not positive, i.e. horizontal or inverted so as to benegative. A diagnosis of subacute cardiac dysfunction that is eithersubacute myocarditis or a cardiomyopathy is then made based on thedetermination of T-wave frequency. More specifically, it has beendiscovered that horizontal or negative T-waves of even a relativelysmall frequency of the total for any given time period can be an earlyindication of subacute cardiac dysfunction which may occur during thecourse of one or several systemic infections following an earlier viralinfection. Chronic or nonproductive viral infection may be the cause,for instance by one of several viruses such as the herpesvirus groupwhich produce these several kinds of multiplication in experimentalanimals and in humans.

While I had previously believed that the cardiac dysfunction was causedby subacute myocarditis, have now discovered that it also can be causedby a noninflammatory cardiomyopathy. Thus, the subacute cardiacdysfunction can be either subacute myocarditis or a cardiomyopathy. Infact, I now believe that in most instances, a cardiomyopathy is thecause for the persistent unexplainable fatigue.

In carrying out the method, it is preferably to utilize a portablemonitor to perform the electrocardiographic monitoring of the ambulatorypatient such that the monitoring can be performed for a prolonged timeperiod during normal daily activity. Most preferably, the data from theelectrocardiographic monitoring is magnetically stored so as tofacilitate its analysis to detect the frequency when the T-wave is notpositive.

In analyzing the electrocardiographic data, the number of cycles whenthe T-wave is not positive during a given time period is utilized as thenumerator of a ratio whose denominator is the total number of cyclesduring the given time period such that multiplication of this ratio by100 gives the percentage of cycles when the T-wave is not positive.

Monitoring of the frequency when the T-wave is not positive can beperformed at different time periods to diagnose the presence andseverity of the patient's subacute cardiac dysfunction. Morespecifically, the frequency when the T-wave is not positive can bedetermined for a time period when the patient's pulse rate is below 100cycles per minute such as during normal activity. Furthermore, thefrequency when the T-wave is not positive can be determined for a timeperiod when the patient's pulse rate is between 100 and 120 cycles perminute such as during modest tachycardia. further, the frequency whenthe T-wave is not positive can be determined for a time period when thepatient's pulse rate is above 120 cycles per minute such as duringsevere tachycardia. In addition, the frequency when the T-wave is notpositive can be determined for a given time period regardless of thepatient's pulse rate. A higher frequency of the T-wave not beingpositive for any given pulse rate or the same frequency of the T-wavenot being positive at a lower pulse rate is believed to be indicative ofmore severe subacute cardiac dysfunction.

The treatment prescribed can be restricting activity, refraining fromthe intake of alcohol, antiviral chemotherapy or immunomodulators. Therecovery is also preferably monitored by performing furtherelectrocardiographic monitoring of the treated ambulatory patient anddetermining the frequency when the T-wave is not positive.

The objects, features and advantages of the present invention arereadily apparent from the following detailed description of the bestmode for carrying out the invention when taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view of an electrocardiogram of a healthy person;

FIG. 2 is a partial view of an ambulatory patient being monitored forsubacute cardiac dysfunction in accordance with the present invention;and

FIGS. 3 and 4 are electrocardiograms illustrating inverted andhorizontal T-waves, respectively, which are utilized to determine thefrequency when the T-wave of the monitored ambulatory patient is notpositive in order to diagnose subacute cardiac dysfunction in accordancewith the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIG. 1 of the drawings, an electrocardiogram of ahealthy person is illustrated and an understanding thereof will behelpful in understanding the electrocardiographic monitoring of thepresent invention. This electrocardiogram includes a PQRST waveformcorresponding to one heart beat cycle. The P-wave is of a positivepolarity and corresponds to an electrical impulse that triggers theheart beat. After the P-wave, there is a quiescent PQ segment that lastsfor approximately 0.04 seconds prior to the QRS segment whichcorresponds to ventricular contractions producing the actual pumping ofthe heart and including a slightly negative initial Q-wave, the largepositive R-wave and the slightly negative S-wave. Following the STsegment, there is a T-wave which corresponds to repolarization of theheart in preparation for the next cycle. It should be noted that it isalready recognized that a persistently negative ST segment which has anegative value throughout as well as persistently depressed or invertedT-waves are already recognized as demonstrating heart scar or ischemiathat would thus explain fatigue according to conventional diagnosis.

The electrocardiographic monitoring findings discussed below wereobserved during a study of a group of 89, 71 being women, who hadfatigue that was not by conventional analysis. All but one of theseindividuals were relatively young, i.e. under 50 years of age, and werepredominantly individuals who previously were relatively active asopposed to lethargic. They did not have hypertensive vascular disease,coronary artery disease, diabetes mellitus or hyperlipidemia which areincreased risk factors for coronary artery occlusion. Eighteen of theindividuals studied had abnormal ventricular dynamics. Nine directbiopsies of the heart (right ventricular endomycardial biopsies) showedone instance of subacute myocarditis and 8 instances of cardiomyopathy.

With reference to FIG. 2, a method for diagnosing subacute cardiacdysfunction is performed in accordance with the present invention byelectrocardiographically monitoring an ambulatory patient 10 who haspersistent unexplainable fatigue, i.e. the patient does not have anelectrocardiogram whose ST segment is persistently depressed or whoseT-waves are persistently inverted. This electrocardiographic monitoringis performed with a monitor 12 as is hereinafter more fully described.In carrying out the method, the frequency is determined when the T-waveof the ambulatory patient is not positive. In other words, this patientmay demonstrate a normal electrocardiogram like that shown in FIG. 1during most of the cycles; however, during a limited number of cyclessuch as on the order of 0.1% or so to 20 or 25% of the total, the T-wavemay be either inverted as shown in FIG. 3 or horizontal as shown in FIG.4 so as thus not to be positive. A determination of this frequency ofthe T-wave not being positive in an ambulatory patient whose fatigue hasnot been heretofore explainable demonstrates subacute cardiacdysfunction that is either subacute myocarditis or a cardiomyopathy mayresult from a viral infection or other unrecognized infectious agentthat precedes the onset of the fatigue usually by a time period ofseveral days or a week or more. While subacute myocarditis may be thecause of the persistent unexplainable fatigue in some instances, I nowbelieve in view of the data discussed above that a cardiomyopathy ismore frequently and perhaps most of the time the cause of the persistentunexplainable fatigue. It may also be possible for both a myocarditisand subacute cardiomyopathy to be the cause.

With continuing reference to FIG. 2, the monitor 12 utilized to performthe electrocardiographic monitoring of the ambulatory patient ispreferably of the portable type so that the patient does not have tostay at the medical facility where the monitoring is commenced and canthus be monitored during normal daily activity. Monitor 12 has fiveleads 14 with connections 16 to the patient's body so that theelectrical charge between different locations can be determined in anyconventional way to provide the electrocardiographic monitoring. Thedata from the electrocardiographic monitoring is preferably magneticallystored such as on a magnetic tape cassette 18 inserted into the monitorin a conventional manner. It should be recognized that the data can alsobe sent from the monitor by telemetry for magnetic storage at a suitablepickup station; however, the magnetic storage by a tape cassette held bythe portable monitor is preferred.

The monitoring was performed both (1) between the two upper leads(normally referred to as "standard lead one") to give an overallmonitoring of the heart, and (2) between the leads connected to the leftshoulder and the center of the chest to monitor the left which providespumping of blood from the heart. However, it should be stated that it isbelieved that the same results will be observed between other leads asthe results herein discussed. Furthermore, the presence of the T-wavesthat are not positive (1) at one particular lead such as the lead thatmonitors the left ventricle, and/or (2) at more than one lead isbelieved to indicate more severe subacute cardiac dysfunction.

The patient is monitored as described above for a given time period suchas normally 6 hours, 12 hours, 18 hours or more conventionally 24 hours,although a greater time can also be monitored, and the number of cycleswhen the T-wave is not positive is counted in any conventional way. Thenumber of cycles when the T-wave is not positive during a given timeperiod may be utilized as the numerator of a ratio whose denominator isthe total number of cycles during the given time period. Thus,multiplication of that ratio by 100 gives the percentage of cycles whenthe T-wave is not positive. Any healthy person may have a limited numberof cycles with the T-wave not being positive during the 80,000 to140,000 or so daily heart beats at a normal pulse rate. However, aperson who has an excessively high frequency of T-waves that are notpositive, about 0.1% or greater, may have cardiac dysfunction such assubacute myocarditis or a cardiomyopathy, that accounts for the fatiguewhich is otherwise unexplainable.

Different ways of monitoring the fatigue can be useful in diagnosing thepatient's heart dysfunction. More specifically, the frequency when theT-wave is not positive may be determined for a time period when thepatient's pulse rate is below 100 cycles per minute such as duringnormal activity. Furthermore, the frequency be determined when theT-wave is not positive for a time period when the patient's pulse rateis between 100 and 120 cycles per minute such as during modesttachycardia. Still further, the frequency when the T-wave is notpositive may be determined for a time period when the patient's pulserate is above 120 such as during severe tachycardia. Finally, thefrequency when the T-wave is not positive may be determined for a giventime period regardless of the patient's pulse rate. All of thisdetermination can be performed with any conventional type ofelectrocardiographic monitoring equipment or conventional equipmentsuitably adapted so that the attending physician does not have toindividually analyze inked tracings of the PQRST waveforms.

The present invention also contemplates treatment of subacute cardiacdysfunction upon diagnosing a patient by the method described above.More specifically, when an ambulatory patient having persistentunexplainable fatigue is electrocardiographically monitored anddetermined to have an excessively high frequency of T-waves that are notpositive, a suitable treatment is prescribed. Preferred treatments to beprescribed include restricting activity and refraining from the intakeof alcohol, with both being preferred. Other treatments includeantiviral chemotherapy and immunomodulators such as cytokines orinterferons. Various combinations of these treatments can also be used.

It is also preferable to monitor the treated patient to determine whenrecovery has been achieved. This further monitoring of the treatedpatient is performed by conducting further electrocardiographicmonitoring of the ambulatory patient, preferably with portable monitor12, and determining the frequency of when the T-wave is not positive.Recovery is heralded by reestablishment of the normally positiveT-waves; in the patients treated as described above, this recovery tookplace in a mean time of about eight months. The restricted activity andrefraining from the intake of alcohol before recovery is believed toprevent permanent heart damage that would result if this treatment werenot followed.

It should also be noted that the extent to which the T-waves arenegative is indicative of more severe subacute cardiac dysfunction. Morespecifically, the integral sum of the negative area of the T-waves canbe totaled for a given time and divided by the total heart beats duringthat time, and the result can be expressed as an index or ratio thatprovides an indication of how severe a case is present. Furthermore, theextent of the negative T-wave can also be measured with a greaternegative value indicating a more severe case of subacute cardiacdysfunction. Recovery is thus indicated by this indicator becomingsmaller as the T-waves are less negative. Also, the extent of thenegative T-wave amplitude correlated with cardiac rate is anotherimportant measure of the severity of the subacute myocarditis orcardiomyopathy.

Furthermore, it should be understood that T-waves normally becomedepressed or inverted when a patient stands up in about 4% or 5% ofpatients. Such positional changes, which usually occur in standard leadIII and precordial leads V₅ or V₆ in the stationary electrocardiogram,are considered in evaluating the results of the presentelectrocardiographic monitoring.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative ways of performing the invention asdefined by the following claims.

What is claimed is:
 1. A method for diagnosing subacute cardiacdysfunction in a patient whose sedentary electrocardiogram ST segmentand T-wave do not indicate cardiac dysfunction, the methodcomprising:electrocardiographically monitoring to detect T-waves of anambulatory patient who has persistent unexplainable fatigue; determiningthe T-wave frequency when the T-wave of the ambulatory patient is notpositive; and providing a diagnosis of subacute cardiac dysfunction thatis selected from the group consisting of subacute myocarditis and asubacute cardiomyopathy based on the determination of T-wave frequency.2. A method for diagnosing subacute cardiac dysfunction as in claim 1wherein a portable monitor is utilized to perform theelectrocardiographic monitoring of the ambulatory patient.
 3. A methodfor diagnosing subacute cardiac dysfunction as in claim 1 wherein thedata from the electrocardiographic monitoring is magnetically stored. 4.A method for diagnosing subacute cardiac dysfunction as in claim 1wherein the number of cycles when the T-wave is not positive during agiven time period is utilized as the numerator of a ratio whosedenominator is the total number of cycles during said given time period.5. A method for diagnosing subacute cardiac dysfunction as in claim 1,2, 3, or 4 wherein the frequency when the T-wave is not positive isdetermined for a time period when the patient's pulse rate is below 100cycles per minute such as during normal activity.
 6. A method fordiagnosing subacute cardiac dysfunction as in claim 1, 2, 3, or 4wherein the frequency when the T-wave is not positive is determined fora time period when the patient's pulse rate is between 100 and 120cycles per minute such as during moderate tachycardia.
 7. A method fordiagnosing subacute cardiac dysfunction as in claim 1, 2, 3, or 4wherein the frequency when the T-wave is not positive is determined fora time period when the patient's pulse rate is above 120 cycles perminute such as during severe tachycardia.
 8. A method for diagnosingsubacute cardiac dysfunction as in claim 1, 2, 3, or 4 wherein thefrequency when the T-wave is not positive is determined for a given timeperiod regardless of the patient's pulse rate.
 9. A method fordiagnosing subacute cardiac dysfunction in a patient whose sedentaryelectrocardiogram ST segment and T-wave do not indicate cardiacdysfunction, the method comprising:utilizing a portable monitor toelectrocardiographically monitor T-waves of an ambulatory patient whohas persistent unexplainable fatigue; magnetically storing theelectrocardiographic data of the patient; determining the T-wavefrequency when the T-wave of the patient is not positive; and providinga diagnosis of subacute cardiac dysfunction that is selected from thegroup consisting of subacute myocarditis and a cardiomyopathy based onthe determination of T-wave frequency.
 10. A method for diagnosing andtreating subacute cardiac dysfunction in a patient whose sedentaryelectrocardiogram ST segment and T-wave do not indicate cardiacdysfunction, the method comprising:electrocardiographically monitoringto detect T-waves of an ambulatory patient who has unexplainablefatigue; determining the T-wave frequency when the T-wave of theambulatory patient is not positive; providing a diagnosis of subacutecardiac dysfunction that is selected from the group consisting ofsubacute myocarditis and a cardiomyopathy when there is an excessivelyhigh frequency of the T-wave not being positive; and prescribing atreatment when subacute cardiac dysfunction is diagnosed.
 11. A methodfor diagnosing and treating subacute cardiac dysfunction as in claim 10wherein the treatment prescribed is selected from the group consistingof restricting activity, refraining from the intake of alcohol,antiviral chemotherapy and immunomodulators.
 12. A method for diagnosingand treating subacute cardiac dysfunction as in claim 10 or 11 whereinrecovery is monitored by performing further electrocardiographicmonitoring of the treated ambulatory patient and determining thefrequency when the T-wave is not positive.
 13. A method for diagnosingand treating subacute cardiac dysfunction in a patient whose sedentaryelectrocardiogram ST segment and T-wave do not indicate cardiacdysfunction, the method comprising:utilizing a portable monitor toelectrocardiographically monitor T-waves of an ambulatory patient whohas persistent unexplainable fatigue; magnetically storing theelectrocardiographic data of the patient; determining the T-wavefrequency when the T-wave of the ambulatory patient is not positive;providing a diagnosis of subacute cardiac dysfunction that is selectedfrom the group consisting of subacute myocarditis and a cardiomyopathy;and prescribing a treatment that includes both restricting activity andrefraining from the intake of alcohol when there is an excessively highfrequency of the T-wave not being positive.
 14. A method for diagnosingand treating subacute cardiac dysfunction as in claim 13 whereinadditional treatment prescribed is selected from the group consisting ofantiviral chemotherapy and immunomodulators.
 15. A method for diagnosingand treating subacute cardiac dysfunction as in claim 13 or 14 whereinfurther electrocardiographic monitoring of the treated ambulatorypatient is performed with the portable monitor to determine thefrequency when the T-wave is not positive in order to determine when thepatient has recovered.
 16. A method for diagnosing subacute cardiacdysfunction in a patient whose sedentary electrocardiogram ST segmentand T-wave do not indicate myocarditis, the methodcomprising:electrocardiographically monitoring to detect-T-waves of anambulatory patient who has persistent unexplainable fatigue; determiningthe extent to which the T-waves of the ambulatory patient are negative;and providing a diagnosis of subacute cardiac dysfunction that isselected from the group consisting of subacute myocarditis andcardiomyopathy based on the determination of the negative extent of theT-waves.
 17. A method for diagnosing subacute cardiac dysfunction as inclaim 16 wherein the extent to which the T-waves are negative isdetermined by totaling the integral sum of the negative area of theT-waves divided by the total heart beats for a given time.
 18. A methodfor diagnosing subacute cardiac dysfunction as in claim 16 wherein theseverity of the subacute cardiac dysfunction is measured by the extentof the negative value of the T-waves.